According to Osho, self-actualization is indeed a basic need: we are born as potential, a seed, and unless we flower into what we are meant to be, an inner sense of lack persists. When potential becomes actual, life culminates in peak experience: effortless contentment, desirelessness, and bliss independent of externals. Though nature doesn’t compel it, fulfilling this inner growth alone ends the feeling of "something missing."
Yes—like a seed must grow into a flower, you need to become who you can truly be, or you’ll always feel something is missing.